It doesn't have to be stressful! I say that but we honestly have the most easy going buddy. If his neither ever gets the suffer we'll be in a weird of literal pain.
On weekdays we test 3-4 times. Before shots in AM and PM, one on Dads lunch if he can swing it, and one before bed, usually around PM+4. It helps me get to sleep if I know he's not dropping off the sugar deep end.
We struggled at the beginning but finally have the hang of it.
We start with lots of pets and scritchies in his designated testing spot with a fuzzy blanket. We do it on the couch because it lowers his chances for scampering off. After he is in full on purr mode, we do the poke.
Some days he minds it less. Some days I go into it stressed and late for work, which stresses him out big time.
Always always have a treat ready for when they finish. Give lots of praise and pets.
When we first started this journey and were struggling to test, I would hear about cats who come when called or at the sound of the strip bottle being shaken. NO WAY, I thought. At this point Gato comes when he hears the sound and sees the treat, sometimes he'll even jump onto the couch.